JP2009138856A - Electrically-driven valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrically driven valve whose stress is reduced which acts on a spot-welded portion between a valve body comprising an elliptical plate and a shaft for turning the elliptical plate with its minor axis defined as a turning center. <P>SOLUTION: There is provided a structure including a groove 22 which is provided in a depressed manner in a surface on a butterfly valve side of an output gear 8 of a motor actuator and axially extends and a lever 21 which is formed by bending the shaft 20 into an L-shape and is fitted into the groove. In the structure, a width of the groove 22 is made larger than a diameter of the lever 21 and flatly-crushing portions 23 are provided on mutually opposed surfaces inside the groove 22 in a protruding manner and further a distance between leading ends of the flatly-crushing portions 23 is made nearly equal to the diameter of the lever 21 to engage the lever 21 at the leading ends of the flatly-crushing portions 23. In the first operation of the valve, therefore, the stress acting on the spot-welded portion leads to a reduction due to the crushing action of the leading end of the flatly-crushing portion 23, and in the second and the subsequent operations, the stress is reduced by the crushed amount of the flatly-crushing portion 23. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electric valve, and more particularly to an electric valve that functions as an on-off valve or a switching valve used in a circulation circuit of a hot water supply complex.

  The hot water supply complex is provided with a circulation circuit for additional preparation of bath water, and an electric valve generally functioning as an on-off valve is interposed in the circulation circuit. As an electric valve for opening and closing such a water circuit, a ball valve is generally known, but a butterfly valve capable of reducing the cost has also been proposed (for example, see Patent Document 1).

  A butterfly valve has a sleeve having elasticity in a cylindrical passage, and a valve body made of an elliptical plate is arranged in the sleeve, and a motor centering on the axis of the minor axis direction of the valve body. The actuator is configured to rotate the valve body. When the valve body is positioned in a direction parallel to the passage, the butterfly valve is fully opened, and when the valve body is rotated and pressed against the sleeve, the butterfly valve is fully closed.

  In addition, the butterfly valve forms a passage in two directions orthogonal to the passage in which the sleeve is provided through the center of rotation of the valve body, thereby allowing water introduced from one inlet to the two-way passage. It is possible to configure a switching valve that switches so that one of the water that is distributed or introduced from the two-way passage flows to one outlet. Of course, by controlling the angle of the valve body, it is possible to adjust the flow rate, or to adjust the distribution or mixing ratio.

In such an opening / closing or switching operation of the butterfly valve, the valve body constituted by a plate is operated by a motor actuator rotationally driving a shaft disposed and joined to a shaft in the minor diameter direction. The opening / closing or switching operation of the butterfly valve is completed by pressing the plate against the sleeve until both ends of the long-diameter direction of the plate are in contact with the sleeve, and further rotating the plate until the sleeve is compressed and deformed. The rotation stop position of the plate at this time is a position further rotated from a position where both ends of the plate in the major axis direction contact the sleeve. This stop position is a stop position by mechanical lock, and is a position where the output gear of the motor actuator that drives the shaft is forcibly stopped by contacting the stopper at both ends of the allowable rotation range. Therefore, when the passage is closed or switched, the entire circumference of the valve body is stopped while the sleeve is compressed, so that a sufficient seal is established between the valve body and the sleeve.
JP 2005-9670 A

  However, since the valve body is assembled by pushing the elliptical plate into the elastic sleeve and then joining the shaft to the plate by spot welding, the spot welds corrode due to aging. This is a part where the fatigue limit stress decreases, and when it receives the load of the motor actuator, it is also a part where repeated stress acts intensively and the fatigue strength decreases. When the critical stress has been reduced, there has been a problem that the plate may be detached from the shaft due to fatigue failure at the spot weld.

  This invention is made in view of such a point, and it aims at providing the motor operated valve which reduced the stress concerning the junction part of a plate and a shaft, and suppressed the fall of fatigue strength. .

  In the present invention, in order to solve the above-mentioned problem, a valve body made of an elliptical plate is rotated around an axis in the short diameter direction in an elastic sleeve provided in a cylindrical passage. A butterfly valve that can be arranged to open / close or change the flow path and a shaft that is connected to the valve body and disposed on the shaft in the short diameter direction are rotationally driven. A motor actuator, and an output gear of the motor actuator has a radially extending groove recessed in the surface on the butterfly valve side, and the tip of the shaft on the motor actuator side is L-shaped. In the motorized valve having a bent lever and transmitting the driving force of the motor actuator to the valve body by fitting the lever into the groove, the groove is The crushing portion has a width larger than the diameter of the lever, and a crushing portion protrudes from the inner facing surface, the distance between the tips of the crushing portions is approximately equal to the diameter of the lever, and the lever There is provided a motor-operated valve fitted in the groove in an engaged state at the tip.

  According to such a motor-operated valve, the tip of the crushing portion is crushed by the lever when the first flow path is opened / closed or switched. Thereby, at the time of opening and closing or switching operation of the flow path for the second and subsequent times, the stress applied to the joint portion between the valve body and the shaft is reduced by the amount of collapse of the crushing portion.

  The motor-operated valve having the above configuration has a crushing portion having a welded portion stress reduction function at the engaging portion between the output gear of the motor actuator and the butterfly valve, so that the operating angle at the position where the valve body starts to close is increased. Therefore, the operating angle range from the closing start position to the gear lock position, that is, the angle range in which the butterfly valve body compresses and deforms the sleeve is reduced, so that the stress applied to the welded portion at the gear lock position can be reduced. There is an advantage that a decrease in fatigue strength can be greatly delayed.

  Even if a displacement occurs in the joint position between the valve element and the shaft that rotates the butterfly valve during manufacture of the butterfly valve, the joint displacement is absorbed by the crushed amount of the crushing portion. It is possible to prevent the partial stress from increasing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, taking as an example a case where the present invention is applied to a three-way control valve for water circuit switching in a circulation circuit of a hot water supply complex.
1 is a front view showing the motor-operated valve according to the present embodiment with the lid removed, FIG. 2 is a plan view showing the motor-operated valve according to the present embodiment, and FIG. 3 is a cross-sectional view taken along the line AA in FIG. FIG. 4, FIG. 4 is a cross-sectional view taken along the line B-B of FIG. 1, FIG. 5 is a perspective view showing an engagement state between the output gear and the shaft, and FIG. It is a characteristic view which shows the change of.

  As shown in FIGS. 1 and 2, the motor-operated valve is arranged at the upper portion of the butterfly valve 1 having one inlet 1 a and two outlets 1 b and 1 c and switching the butterfly valve 1. And a motor actuator 2 to be controlled. Note that the motor actuator 2 is shown in a state in which the lid that should be put on the body 3 common to the butterfly valve 1 is removed in FIGS.

  As is often seen in the plan view of FIG. 2, the motor actuator 2 includes a motor 4, and a worm 5 is provided on the output shaft thereof. The worm 5 is meshed with a worm gear 6, and a small-diameter gear (not shown) formed to operate integrally with the worm gear 6 is meshed with the intermediate gear 7. The intermediate gear 7 has a small-diameter gear 7 a (see FIG. 4) (not shown) formed so as to operate integrally with the intermediate gear 7, and is engaged with the output gear 8. The worm 5 to the output gear 8 constitute a speed reducer that transmits the driving force in only one direction.

  The output gear 8 has a sector shape, and both circumferential ends thereof have contact surfaces 9 and 10. The body 3 that rotatably supports the output gear 8 is integrally formed with stoppers 11 and 12 that face the contact surfaces 9 and 10 in the circumferential direction. As a result, when the output gear 8 is rotated counterclockwise, the contact surface 9 abuts against the stopper 11, and when rotated in the clockwise direction, the contact surface 10 abuts against the stopper 12 to force Therefore, the rotation range of the output gear 8 is restricted. The output gear 8 is configured to directly switch and drive the butterfly valve 1.

  As shown in FIG. 3, the butterfly valve 1 has a body 3 having a shape in which a first passage 13 extending in the vertical direction in the drawing and a second passage 14 extending in the horizontal direction in the drawing intersect. One end of the first passage 13 constitutes the inlet 1 a of the butterfly valve 1, and the other end is closed by a plug 15. Both ends of the second passage 14 constitute outlets 1b and 1c of the butterfly valve 1, respectively.

  The first passage 13 is lined by a rubber sleeve 16, and two communication holes 17 and 18 are passed through correspondingly to the second passage 14. A valve body 19 formed of a plate is disposed in the sleeve 16. The valve body 19 is joined by spot welding to a shaft 20 that hangs down through the center of intersection of the first passage 13 and the second passage 14, and is configured to be rotatable about the shaft 20. The valve body 19 and the shaft 20 are each made of stainless steel having excellent corrosion resistance against water.

  The valve body 19 has an elliptical shape, and when the major axis is at the angle of the switching position with respect to the central axis of the first passage 13, the projected shape from the direction of the central axis is a perfect circle. The minor axis is formed larger than the inner diameter of the sleeve 16. As a result, when the butterfly valve 1 is switched, both ends of the valve body 19 in the short diameter direction are sealed by biting into the sleeve 16, and the other peripheral portions are sealed by being pressed against the sleeve 16.

  The shaft 20 that fixes the valve body 19 is rotatably held by the body 3, but in order to prevent water from leaking through the clearance with the body 3 that supports the motor actuator 2 side. It is sealed by the shaft seal part. Although not shown, the shaft seal portion has an O-ring and a flat washer, and the flat washer is fixed by a retaining ring from the motor actuator 2 side.

  As shown in FIGS. 4 and 5, the shaft 20 has a lever 21 formed by bending the tip on the motor actuator 2 side into an L shape, and this lever 21 is a butterfly valve 1 of the output gear 8. It is fitted in a groove 22 which is recessed in the side surface (lower surface) and which is long in the radial direction. The groove portion 22 has a width larger than the diameter of the lever 21, and a mountain-shaped crushing portion 23 projects from the inner facing surface. The distance between the tips of the crushing portion 23 is roughly the diameter of the lever 21. To be equal. The crushing portion 23 is a portion where the tip is crushed and plastically deformed when the lever 21 receives an excessive load from the output gear 8, thereby reducing the stress applied to the spot welded portion. have. With this configuration, the rotational movement of the output gear 8 is transmitted to the shaft 20 through the crushing portion 23 and the lever 21 in a state where the load is limited.

  In this embodiment, the output gear 8 is made of resin, and in the illustrated example, the pair of crushing portions 23 that are the stress reduction function of the welded portion are provided on the opposing surfaces near the center in the longitudinal direction of the groove portion 22. Yes. However, the crushing portions 23 may be provided on the shaft 20 side or the distal end side of the lever 21 depending on the material of the output gear 8, or a plurality of pairs may be provided along the longitudinal direction of the groove portion 22 as necessary. . Further, the shape of the crushing portion 23 is not limited to the mountain shape as shown in the figure, and may be a triangle as long as the distal end portion is narrower than the base end portion and can be easily crushed.

  In the motor-operated valve having the above configuration, for example, when controlling the butterfly valve 1 toward the switching position as shown in FIG. 3, the motor 4 is rotated in a certain rotational direction, and the output gear 8 is rotated counterclockwise in FIG. Will be rotated. At this time, a load is hardly applied to the spot welded portion between the valve body 19 and the shaft 20. FIG. 6 is a characteristic diagram showing a change in welded portion stress with respect to the operating angle θ of the valve body 19, but at the position of the operating angle θ = 0 where the edge of the long axis of the valve body 19 does not hit the sleeve 16. The weld stress is substantially zero. Note that the fatigue limit stress shown in this characteristic diagram is set in anticipation of corrosion under corrosive environments, and even if the fatigue limit stress is reduced due to corrosion, the weld zone stress at the gear lock position is the fatigue stress. It does not fall below the critical stress.

  When the output gear 8 further rotates counterclockwise from the position where the operating angle θ = 0, the butterfly valve 1 is in the first passage 13 at the first closing start position where the valve body 19 hits the rubber sleeve 16. The closing of the passage extending from the inlet 1a to the outlet 1b of the second passage 14 through the communication hole 17 is started. Thereafter, the valve body 19 is rotated while compressing the sleeve 16, and finally the mechanical lock that forcibly stops the rotation of the output gear 8 by the contact surface 9 of the output gear 8 abutting against the stopper 11. The rotation of the valve body 19 stops and the switching operation ends. At this time, one of the crushing portions 23 projecting from the opposing surface of the groove portion 22 is crushed by the lever 21 during the first mechanical lock.

  Similarly, even when the output gear 8 is driven to rotate in the clockwise direction in FIG. 2, first, the butterfly valve 1 is in the first passage at the first closing start position where the valve body 19 hits the rubber sleeve 16. The closing of the passage extending from the inlet 13 of 13 to the outlet 1c of the second passage 14 through the communication hole 18 is started. Thereafter, the valve body 19 is rotated while compressing the sleeve 16, and finally, by a mechanical lock in which the contact surface 10 of the output gear 8 abuts against the stopper 12 and the rotation of the output gear 8 is forcibly stopped. The rotation of the valve body 19 stops and the switching operation ends. At this time, the other of the crushing portions 23 projecting from the opposing surface of the groove portion 22 is crushed by the lever 21 during the first mechanical lock.

  Thus, in the switching operation after the first time, the operating angle θ of the closing start position of the butterfly valve 1 is increased by the amount of collapse of the crushing portion 23, and the closing start position is the second and subsequent closing start positions shown in FIG. The movement angle range (the rubber compression range of the sleeve 16) from the closing start position to the gear lock position becomes smaller. At this time, the welded portion stress at each switching completion position in the gear lock position is substantially equal, and is further reduced than the welded portion stress in the conventional case.

  Since the welded portion stress at each gear lock position becomes substantially equal, even if the joint position between the valve body 19 and the shaft 20 is slightly deviated at the time of manufacture, the deviation can be absorbed. That is, the valve body 19 and the shaft 20 must be spot-welded at a position where the central angle is 0 degree. However, if the joint position is shifted, the stress at the welded portion becomes small at one gear lock position and becomes the fatigue limit. Although it moves away from the stress, it becomes larger at the other gear lock position and approaches the fatigue limit stress. However, in the motor-operated valve having the above-described configuration having the crushing portion 23, first, one of the crushing portions 23 is crushed small when going to one gear lock position, and the other of the crushing portions 23 is crushed greatly when going to the other gear lock position. Therefore, the welding portion stress is averaged by being smaller than that before each crushing portion 23 is crushed.

  In addition, since the margin between the weld stress at the gear lock position and the fatigue limit stress is increased, even if the fatigue limit stress is reduced due to corrosion of the weld, the decrease in fatigue strength until fatigue failure is delayed. be able to.

  Further, the timing is set such that the valve body 19 is pressed against the rubber sleeve 16 immediately before the contact surfaces 9 and 10 of the output gear 8 abut against the stoppers 11 and 12. It is possible to absorb an impact when mechanically locked by the motors 11 and 12, thereby suppressing a decrease in fatigue strength.

  The above description has been made on the three-way switching control valve, but the same applies to an on-off valve and a four-way switching control valve. Further, since the crushing portion 23 can be crushed to allow the engaging portion between the output gear 8 and the lever 21 to play, it is basically unsuitable for application to a flow control valve, but requires an accurate opening-flow rate characteristic. If the motor valve is not used, or if it is a motor valve in which the feedback control of the flow rate is used in combination with the control of the motor actuator 2, it is possible to apply the above-described weld stress reduction function.

  In the above-described embodiment, the crushing portion 23 formed integrally with the output gear 8 and plastically deformed is shown as a configuration having a weld portion stress reduction function. However, a deformable member that is elastically deformed, such as rubber (harder than the sleeve 16), a leaf spring, or the like, is interposed in the groove portion 22 between the lever 21 and the output gear 8, and the deformation is performed from the closing start position. Even if the member is started to be deformed, the same welded portion stress reduction effect can be obtained, but the number of parts and the number of assembly steps increase, which is not a preferable choice.

It is a front view which shows the electric valve which concerns on this Embodiment in the state which removed the cover. It is a top view which shows the motor operated valve which concerns on this Embodiment. It is AA arrow sectional drawing of FIG. It is BB arrow sectional drawing of FIG. It is a perspective view which shows the engagement state of an output gear and a shaft. It is a characteristic view which shows the change of the stress concerning the welding part of the motor operated valve which concerns on this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Butterfly valve 1a Inlet 1b, 1c Outlet 2 Motor actuator 3 Body 4 Motor 5 Worm 6 Worm gear 7 Intermediate gear 7a Gear 8 Output gear 9, 10 Contact surface 11, 12 Stopper 13 1st passage 14 2nd passage 15 Plug 16 Sleeve 17, 18 Communication hole 19 Valve body 20 Shaft 21 Lever 22 Groove part 23 Crushing part

Claims (4)

A valve body made of an elliptical plate is placed in a sleeve having elasticity in a cylindrical passage so that it can rotate around its axis in the short diameter direction, and the flow path is opened or closed or switched. A butterfly valve for rotating the shaft, and a motor actuator that rotationally drives a shaft that is disposed on and joined to the valve body in the axis of the short diameter direction, but whose rotation range is defined by a mechanical lock. The output gear has a radially extending groove that is recessed in the butterfly valve side surface, and has a lever whose tip on the motor actuator side of the shaft is bent in an L-shape. In the electric valve adapted to transmit the driving force of the motor actuator to the valve body by fitting in the groove portion,
The groove portion has a width larger than the diameter of the lever, a crushing portion projects from the inner facing surface, the distance between the tips of the crushing portions is approximately equal to the diameter of the lever, and the lever The motor-operated valve fitted in the groove part in an engaged state at the tip of the crushing part.   The motor-driven valve according to claim 1, wherein a plurality of pairs of the crushing portions are provided along a radial direction of the groove portion.   The motor-driven valve according to claim 1, wherein the crushing portion has a mountain shape whose tip is narrower than a base end of the groove portion on a facing surface side.   The motor-driven valve according to claim 1, wherein the crushing portion has a triangular shape with a tip that is narrower than a base end on the opposite surface side of the groove.

Images